1. Field of the Invention
The present invention relates to an anti-shake apparatus for a photographing device (apparatus), and in particular to a position-detecting apparatus for a movable unit that includes the imaging device etc., and that can be moved for correcting the hand-shake effect.
2. Description of the Related Art
An anti-shake apparatus for a photographing apparatus is proposed. The anti-shake apparatus corrects for the hand-shake effect by moving a hand-shake correcting lens or an imaging device on a plane that is perpendicular to the optical axis, corresponding to the amount of hand-shake which occurs during imaging.
Japanese unexamined patent publication (KOKAI) No. 2002-229090 discloses an anti-shake apparatus for a photographing apparatus. The anti-shake apparatus performs a moving operation of a movable unit, which includes a hand-shake correcting lens, by using a permanent magnet and a coil, and a position-detecting operation of the movable unit, by using a hall element and a permanent magnet.
However, in the position-detecting operation, the initial-adjustment operation which adjusts the detecting-resolution in the A/D converting operation for a signal output from the hall element, is performed by changing the value of an amplification rate in the hall-element signal processing circuit. The value of the amplification rate can be changed by changing the value of a resistor in the hall-element signal-processing circuit, so that changing the value of the resistor needs a mechanical adjustment. Accordingly, this initial-adjustment operation is a problem.